1. Field of the Invention
This invention relates to an intake valve assembly for use in a four cycle internal combustion engine, and specifically to an improved poppet valve assembly that utilizes two poppet valve bodies for each port, each of said poppet valve bodies having one or more apertures. When the valve is closed, the valve bodies are sealed in contact against each other with the apertures in each body non-aligned When the valve is open, the valve bodies are separated permitting intake charge to flow through the apertures in each valve body. The purpose of the invention is to quantatively increase the available port opening area of an intake port for optimum charge flow into the combustion chamber resulting in greater volumetric efficiency. With the present invention valve lift distance can be less than the lift distance used with a conventional poppet valve.
2. Description of the Prior Art
A poppet valve has long been used as an intake or exhaust valve in four cycle combustion engines. As conventionally used, a single poppet valve opens or seals closed an intake or exhaust port during predetermined periods of engine operation. One of the inherent problems with the use of a poppet valve is its geometric shape and its location with the respect to a port opening. The available window or opening area that receives the charge flow when the valve is in the open position is dramatically limited by the valve body itself blocking the flow, requiring extensive valve lift per cycle. With the limited amount of time available for the valve to be open, there is not enough opening area to achieve a desired volumeteric efficiency during the intake cycle. A complete discussion of this problem is provided in applicant's U.S. patent application Ser. No. 312,871 filed Oct. 19, 1981 now pending, reference to which is herein made.